Transcription: Cloud formation begins on the ground as water from the Earth's surface constantly evaporates into the air. Cooler, heavier air and the air pressure around mountainous regions pushes this water vapor up into the sky where it expands and cools. When the temperature of the water vapor falls below the temperature of the air around it, excess water vapor condenses as droplets onto microscopic particles such as sea salt, dust and smoke suspended in the air. Masses of these droplets form clouds. When they become too heavy to be held in the cloud, they fall, either evaporating on their descent or reac ...
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